1. Field of the Invention
The present invention relates to a method of detecting localization of an acoustic image through which it is detected how a tone is heard by a listener when a sound is emitted in a specific direction at a specific distance, and an acoustic image localizing system utilizing detection results thereof, and more particularly, relates to such an acoustic image localizing system capable of localizing an acoustic image to various places with stereo loudspeakers provided at fixed positions.
2. Description of the Prior Art
At the present time, stereo reproduction systems are designed so as to produce tones of different output levels at a plurality of (right and left) channels, thereby giving the localization of the tone (acoustic image). Two channels, if provided therein, allows a tone to be localized in a two-dimensional manner between two output devices (loudspeakers), and four channels allows an acoustic image to be localized more clearly.
However, there cannot be provided sufficient localization sensation of an acoustic image by such a method in which the localization is represented only by output levels (or ratio) of right and left channels, i.e. differences in sound volume heard by right and left ears. In actual cases, when a sound source (e.g. musical instrument) is placed in a specific direction at a specific distance, not only volume differs between tones heard by right and left ears, but also some differences in the way a tone sounds and moreover those due to subtle time lags are involved as well. Conventional stereo reproduction systems and the like have been incapable of representing such differences, and therefore incapable of obtaining localization as clear as that obtained when musical instruments are actually laid out.